Question

我做了很小的休息以学习休息。没有使用EntityManager它运行正常。但是当我使用EntityManager时，它会给NPE。我正在使用jboss-eap-6.2，EJB 3，JPA。谷歌后，错误发现EntityManager为空。如何解决这个问题。

@Stateless
@Path("/dili")

public class TestResource {

   @PersistenceContext(unitName = "AjaxrestPU")
   private EntityManager em;

   @GET
   @Path("{key}")
   @Produces("application/xml")
   public Customer getMsg(@PathParam("key") int key) {
      Customer cu = em.find(Customer.class, 1);
      System.out.println("key " + key);

      return cu;
   }

  //return "okkkk";
}

persistance.xml

 <persistence-unit name="AjaxrestPU" transaction-type="JTA">
   <provider>org.hibernate.ejb.HibernatePersistence</provider>
   <jta-data-source>java:/tutes</jta-data-source>
   <exclude-unlisted-classes>false</exclude-unlisted-classes>
   <properties>
     <property name="hibernate.hbm2ddl.auto" value="create"/>
     <property name="hibernate.dialect" value="org.hibernate.dialect.MySQLDialect"/>
   </properties>
</persistence-unit>

老板错误

13:09:38,862 ERROR [org.apache.catalina.core.ContainerBase.[jboss.web].[default
host].[/Ajaxrest].[org.test.ApplicationConfig]] (http-/127.0.0.1:8080-2) JBWEB0
0236: Servlet.service() for servlet org.test.ApplicationConfig threw exception:
org.jboss.resteasy.spi.UnhandledException: java.lang.NullPointerException
    at org.jboss.resteasy.core.SynchronousDispatcher.handleApplicationExcep
ion(SynchronousDispatcher.java:365) [resteasy-jaxrs-2.3.7.Final-redhat-2.jar:2.
.7.Final-redhat-2]

Answer 1

经过2小时的搜索找到答案。在web-inf中创建空beans.xml。那一切。 https://netbeans.org/bugzilla/show_bug.cgi?id=231595

其余的ws中EntityManager为null

1 个答案: